PIC16LC74A-04I/PQ - 8-Bit 4MHz CMOS MCU | Microchip
MPN: PIC16LC74A-04I/PQ ✗ Cuối đờiPIC16LC74A-04I/PQ Tóm tắt
What is an OTP microcontroller? An OTP (One-Time-Programmable) microcontroller is a programmable IC whose on-chip program memory can be written exactly once after manufacture using a programming device. Unlike Flash-based MCUs (such as the PIC16F family) that allow in-circuit re-programming, OTP variants are optimized for cost-sensitive production runs where firmware is final and will never be updated in the field. The PIC16LC7x sits in Microchip's PIC16C mid-range architecture family - a RISC Harvard-architecture 8-bit core with 14-bit instruction words - bridging simple 8-bit controllers and more capable 16-bit PICs.
Key features include an operating voltage range of 3.0V to 6.0V (the 'LC' prefix denotes the low-voltage CMOS variant), 5 mA typical operating current at 4 MHz/5V, an internal watchdog timer with on-chip RC oscillator for safe recovery from code lockups, and a power-on reset (POR) plus brown-out reset (BOR) circuit for reliable supply supervision.
The 44-pin MQFP package is the largest MPN in the PIC16C7x family, providing dedicated pins for parallel port expansion, multiple interrupt sources, and an external memory interface. The 33 I/O pins can drive LEDs, keypads, character LCDs, and small relays directly through current-limited outputs.
Typical applications include industrial control boards, appliance user interfaces, security and alarm panels, automotive body electronics, sensor conditioning front-ends, and low-cost embedded products where OTP cost savings outweigh the need for field re-programmability. The integrated ADC makes it suitable for direct thermistor, potentiometer, and transducer signal acquisition.
When designing with this MPN, allocate board space for an in-system programming header if you plan to use a compatible Flash sibling (PIC16F74) during development - the pinout is identical so the same PCB can host either OTP (production) or Flash (prototype) parts. The PQ suffix denotes the Metric QFP tray package; the industrial (-I) suffix guarantees -40C to +85C operation.
This page consolidates distributor pricing, drop-in pin-compatible substitutes, and practical layout notes for the PIC16LC74A-04I/PQ that supplement the original Microchip datasheet, helping engineers validate the part for legacy designs and production runs.
Bộ thay thế dễ dàng lắp đặt cho PIC16LC74A-04I/PQ — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với PIC16LC74A-04I/PQ (cùng hình factor và footprint) — khác nhau ở Package, Program Memory Size, Timers, A/D Converter, Core Architecture.
PIC16LC74A-04/PQ
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16LC74AT-04I/PQ
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16LC74B-04I/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC16F74-I/PQ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC16F74A-I/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
PIC16C74A-04E/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC16C74B-04E/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC16LC74A-04I/PQ Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC16C RISC, 8-bit, 14-bit instructions |
| Family | PIC16C7x mid-range |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Tần số xung maksimum | 4 MHz |
| Operating Voltage Range | 3.0 V to 6.0 V |
| I/O Pin Count | 33 |
| ADC | 8 channels, 8-bit |
| Timers | 2 x 8-bit Timer0/Timer2, 1 x 16-bit Timer1 |
| Capture/Compare/PWM (CCP) | 1 module |
| Serial Interfaces | USART/SCI, SSP (SPI / I2C) |
| Watchdog Timer | Yes, internal RC-based WDT |
| Reset Circuitry | POR (Power-On Reset), BOR (Brown-Out Reset) |
| Hộp | 44-MQFP (10x10 mm), PQ suffix tray |
| Khoảng nhiệt độ hoạt động | -40C to +85C (Industrial, -I suffix) |
| Kiểu lắp đặt | Surface Mount (QFP) |
| Trạng thái RoHS | unknown |
| Lead-Free / Pb-Free | unknown |
Cấu hình chân PIC16LC74A-04I/PQ
| Chân 1 | /MCLR/VPP — Master Clear (reset) input / Programming voltage input |
| Chân 2 | RA0/AN0 — Port A bit 0 / Analog input channel 0 |
| Chân 3 | RA1/AN1 — Port A bit 1 / Analog input channel 1 |
| Chân 4 | RA2/AN2 — Port A bit 2 / Analog input channel 2 |
| Chân 5 | RA3/AN3/VREF — Port A bit 3 / Analog input channel 3 / ADC voltage reference |
| Chân 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Chân 7 | RA5/AN4/SS — Port A bit 5 / Analog input channel 4 / SPI slave select |
| Chân 8 | RE0/RD/AN5 — Port E bit 0 / Parallel port read / Analog input channel 5 |
| Chân 9 | RE1/WR/AN6 — Port E bit 1 / Parallel write / Analog input channel 6 |
| Chân 10 | RE2/CS/AN7 — Port E bit 2 / Parallel chip select / Analog input channel 7 |
| Chân 11 | VDD — Positive supply (3.0V to 6.0V) |
| Chân 12 | VSS — Ground |
| Chân 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Chân 14 | OSC2/CLKOUT — Oscillator output / clock output (Fosc/4) |
| Chân 15 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Chân 16 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator input / CCP2 output |
| Chân 17 | RC2/CCP1 — Port C bit 2 / CCP1 (Capture/Compare/PWM) output |
| Chân 18 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Chân 19 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Chân 20 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Chân 21 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Chân 22 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Chân 23 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Chân 24 | RC5/SDO — Port C bit 5 / SPI data out |
| Chân 25 | RC6/TX/CK — Port C bit 6 / USART TX / USART clock |
| Chân 26 | RC7/RX/DT — Port C bit 7 / USART RX / USART data |
| Chân 27 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Chân 28 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Chân 29 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Chân 30 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Chân 31 | VSS — Ground |
| Chân 32 | VDD — Positive supply (3.0V to 6.0V) |
| Chân 33 | RB0/INT — Port B bit 0 / External interrupt input |
| Chân 34 | RB1 — Port B bit 1 |
| Chân 35 | RB2 — Port B bit 2 |
| Chân 36 | RB3 — Port B bit 3 |
| Chân 37 | RB4 — Port B bit 4 |
| Chân 38 | RB5 — Port B bit 5 |
| Chân 39 | RB6/PGC — Port B bit 6 / ICSP clock (programming/debug) |
| Chân 40 | RB7/PGD — Port B bit 7 / ICSP data (programming/debug) |
| Chân 41 | NC — Not connected (no internal bond) |
| Chân 42 | NC — Not connected (no internal bond) |
| Chân 43 | NC — Not connected (no internal bond) |
| Chân 44 | NC — Not connected (no internal bond) |
Ứng dụng tiêu biểu
PIC16LC74A-04I/PQ phù hợp cho 6 Áp dụngs: Industrial Control Boards, Appliance User Interfaces, Security and Alarm Panels, Sensor Conditioning Front-Ends, Automotive Body Electronics, Low-Cost Embedded Products (Cost-Down Production).
Industrial Control Boards
The PIC16LC74A-04I/PQ suits industrial control boards thanks to its 33 I/O pins, 8-channel 8-bit ADC, and industrial -40C to +85C operating range. With 192 bytes of RAM and 7 KB OTP program memory, it can scan a 4x4 keypad, drive an alphanumeric LCD, and poll multiple analog sensors (thermistors, pressure transducers) in a deterministic loop. The PIC16C RISC core executes one instruction per four oscillator clocks at 4 MHz, yielding 1 MIPS - enough for PID loops at modest sampling rates. The integrated USART and SSP (SPI/I2C) interface to motor-driver pre-regulators, EEPROM parameter storage, and isolated RS-485 transceivers. OTP cost optimization pays off in high-volume panels where firmware is locked at production.
Được đề xuất
Appliance User Interfaces
For appliance front-panel controllers (washing machines, microwave ovens, dishwasher HMIs), the PIC16LC74A-04I/PQ delivers the right peripheral mix. Its 33 I/O pins can directly drive 7-segment LED displays, multiplexed keypads, and status-indicator LEDs without external drivers. The 8-bit ADC reads temperature sensors, water-level probes, and humidity elements, while the CCP module generates PWM for buzzer tones and small DC motor speed control. The 3.0V to 6.0V supply range accommodates 5V-regulated appliance rails, and the industrial temperature grade survives behind-machine environments. OTP memory locks UI firmware at production, preventing end-user firmware tampering - a regulatory plus for safety-certified appliances.
Được đề xuất
Security and Alarm Panels
The PIC16LC74A-04I/PQ fits security/alarm control panels where its 33 I/O pins can monitor up to 16 zones (with key-switch multiplexing), drive a siren driver, and read a 4x4 keypad. The integrated 8-channel ADC monitors backup-battery voltage, PIR sensor analog outputs, and glass-break detectors. The USART links to a digital dialer or central-station modem, while the SSP (I2C mode) connects to a serial EEPROM that stores event logs and installer codes. Brown-out reset (BOR) and watchdog timer (WDT) ensure recovery from power glitches and code lockups - both critical for unattended alarm systems. OTP locks the firmware to prevent reverse-engineering of proprietary encryption routines.
Được đề xuất
Sensor Conditioning Front-Ends
Use the PIC16LC74A-04I/PQ as a sensor conditioning front-end that reads multiple transducers and outputs a conditioned 4-20 mA or RS-485 signal. Its 8-channel 8-bit ADC digitizes up to eight analog inputs (thermocouple amplifiers, strain-gauge bridges, pH probes) at moderate sampling rates. The 7 KB OTP program memory fits calibration routines, linearization tables, and Modbus RTU protocol stacks. The integrated USART talks directly to RS-485 transceivers for industrial networking, while the CCP module generates excitation pulses for RTD and thermistor sensors. The 44-MQFP footprint exposes all 33 I/O for parallel sensor matrix designs.
Được đề xuất
Automotive Body Electronics
Body-control modules (mirror adjusters, seat controllers, climate panel interfaces, aftermarket alarm systems) historically used the PIC16LC74A-04I/PQ. The 33 I/O pins drive multiple brushed motors via relay arrays, scan keypad matrices, and read thermistor temperature sensors. The 8-bit ADC monitors battery voltage (12V automotive bus) and analog position feedback from potentiometers. The industrial -40C to +85C temperature range covers cabin environments, though under-hood designs require the AEC-Q100 qualified PIC16LC74A-04I/PQ automotive-grade equivalent. The USART connects to body-network LIN bus transceivers for sub-bus expansion.
Được đề xuất
Low-Cost Embedded Products (Cost-Down Production)
The OTP program memory makes the PIC16LC74A-04I/PQ the lowest unit-cost option in the PIC16C7x family once firmware is locked, ideal for cost-sensitive consumer products where field firmware updates are not required. Examples include electronic toys, low-end remote controls, simple point-of-sale terminals, and disposable medical accessories. Design teams typically prototype with the Flash PIC16F74-I/PQ (identical pinout and peripherals) and switch to the PIC16LC74A OTP for production runs once firmware is final. The 192-byte RAM, 7 KB code space, and 4 MHz clock are sufficient for menu navigation, button debouncing, simple sound playback, and LCD text rendering.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC16LC74A-04I/PQ — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | PIC16LC74A-04/PQ | PIC16LC74AT-04I/PQ | PIC16LC74B-04I/PQ | PIC16F74-I/PQ | PIC16F74A-I/PQ |
|---|---|---|---|---|---|---|
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory Type | OTP (7 KB / 4K x 14) | OTP (7 KB) - same | OTP (7 KB) - same | OTP (7 KB) - same | Flash (7 KB) - re-programmable | Flash (7 KB) - re-programmable |
| Maximum Clock Frequency | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 20 MHz - faster | 20 MHz - faster |
| Operating Voltage Range | 3.0 V to 6.0 V | 3.0 V to 6.0 V - same | 3.0 V to 6.0 V - same | 3.0 V to 6.0 V - same | 3.0 V to 6.0 V - same | 3.0 V to 6.0 V - same |
| I/O Pin Count | 33 | 33 - same | 33 - same | 33 - same | 33 - same | 33 - same |
| ADC Channels x Resolution | 8 x 8-bit | 8 x 8-bit - same | 8 x 8-bit - same | 8 x 8-bit - same | 8 x 8-bit - same | 8 x 10-bit - higher resolution |
| Operating Temperature Range | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) - same | -40C to +85C (Industrial) - same | -40C to +85C (Industrial) - same | -40C to +85C (Industrial) - same |
| Lifecycle Status (as of 2026-09-22) | Obsolete | Obsolete | Obsolete | Obsolete | Active (recommended migration) | Active (recommended migration) |
Bảo phân biệt quan trọng
- Largest I/O count and ADC channel count in the PIC16C7x family (vsPIC16LC73A-04I/SO)
- Low-voltage CMOS (LC) variant enables 3.0V operation (vsPIC16C74A-04E/PQ)
- OTP program memory locks firmware at production (vsPIC16F74-I/PQ)
Ghi chú thiết kế
The PIC16LC74A-04I/PQ operates from 3.0V to 6.0V; place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair (pins 11/12 and 31/32) and a bulk 10 uF tantalum or aluminum-polymer capacitor at the supply entry point. Use the on-chip Brown-Out Reset (BOR) by configuring the configuration fuses for the lowest threshold above the minimum operating voltage - this guarantees a clean reset when the rail droops below 3.0V under motor inrush.
OTP (One-Time-Programmable) memory cannot be erased. Once the PIC16LC74A-04I/PQ is programmed, any code bug requires a new physical part. Always prototype with the Flash PIC16F74-I/PQ (identical 44-MQFP pinout, identical peripherals per datasheet 30390E) and only commit to the OTP PIC16LC74A once firmware is locked. Stock a small Flash inventory as a development hedge before placing the OTP production order.
The 44-MQFP (10x10 mm) package uses 0.8 mm pitch gull-wing leads - allocate 0.4 mm copper pads with 0.2 mm mask expansion for hand-reworkability. Place the crystal/oscillator (pins 13/14) within 10 mm of the IC with a ground guard ring and route OSC1/OSC2 traces over a continuous ground pour to minimize EMI coupling. The /MCLR pin (pin 1) needs a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for noise immunity.
Thông tin tuân thủ
Obsolete Microchip PIC16LC74A-04I/PQ from 1990s vintage. RoHS, lead-free, halogen-free status was not explicitly listed in the Verified Web Data and should be confirmed against the latest Microchip product declaration before new-design integration. The part is not AEC-Q100 qualified; for automotive body-electronics applications requiring formal qualification, use the AEC-Q100 graded PIC16F74A-I/PQ Flash equivalent instead.
